US2193298A - Method of producing muntin bar structures - Google Patents

Description

March 1940- E. A. SCHOTTENBERG 3,

METHOD OF PRODUCING MUNTIN BAR STRUCTURES Filed Oct. 11, 1938 2 Sheets-Sheet l Lfl 2?.6. 10 77 s I w EJ7- Jchoiienbeg March 12, 1940. E. A. SCHOTTENBERG 2,193,298

METHOD OF PRODUCING MUNTIN BAR STRUCTURES Filed Oct; 11, 1938 2 Sheets-Sheet 2 11 Schaifienbe y,

Patented mieiz e io UNITED STATES PATENT OFFICE METHOD OF PRODUCING MUNTIN BAR STRUCTURES Elmon A. Schottenberg, Youngstown, Ohio, as-

signor to Truscon Steel Company, Youngstown,

Ohio, a corporation of Michigan Application October 11, 1938, Serial No. 234,485

3 Claims.

This invention relates to a method of producing muntin bar structures for use in window sashes to support window. panes, or for use in grilles and the like or equivalent structures.

Heretofore, in forming muntin bar structures comprising bar sections extending, in efiect, in

crossing, right angular or other desired angular relationship to each other, the usual practice has given joint required the cutting of three bar sections and the making of two separate welded joints, one between each of the pair of bar secture whichgreatly reduces the number of parts necessary to make the, glass holding area of. a sash, andlikewise reduces the number of operasulting in speeding up fabrication and reducing ultimate costs, while providing both a structurally strongerand tighter finished product, wherein the infiltration of air is practically nil.

with the foregoing general objects in view, the invention consists in the novel method steps employed in fabricating same, as will be hereinafter more fully described, illustrated in the accompanying drawings and defined in the appended claims.

In the accompanying drawings, wherein like characters of reference denote corresponding parts in the different views:

Figure 1 is aside elevation of a fragment of a stock bar of one suitable sectional shapefor use in forming muntin bar structures in accordance with the invention.

Figure 2 is a cross section through the bar 50 fragment shown in Figure 1.

Figure 3 is a plan view of the bar fragment shown in Fig. 1, illustrating the first method step of the present invention.

Figure 4 is a plan view illustrating the second ;5 method stepot the present invention.

tions involved in making or assembling, thus re- Figure 5 is a plan view illustrating the third method step of the present invention.

Figurefi is a cross sectional view illustrating the initial part of the third method step of the invention.

Figures 7 and 8 are plan views illustrating different ways of forming muntin bar structures in accordance with the invention,

Figure 9 is an elevation of a window sash equipped with a muntin bar structure produced in accordance with the invention; and

Figure 10 is a detail plan view illustrating a construction in which the sections of the bars have an acute angular relationship to each other.

Referring to the drawings in detail, it will be observed that the bar stock A from which the present improved muntin bar structure is formed, is illustrated in the present instance as being of T-shape in cross section, embodying a web l0 and a flange I l extending laterally from each side of said web. This is a form of bar commonly employed in the fabrication of sash mutins, and therefore has been chosen for purposes of illustration in the present instance. It is to be understood, however, that the bar stock may have other cross sectional shapes, depending upon the purpose it is to serve. For example, it may be of I-shape, L-shape, U-shape or H-shape in cross section or, within the broader aspects of the invention, it may even be flangeless and simply of rectangular, circular or other desired cross sectional shape, as will hereinafter become more, fully apparent. p

According to the present invention in its broader aspects, in order to provide a muntin bar structure comprising. four bar sections extending, in effect, in crossing, right angular or other desired angular relationship, only two bar sections are required and only a single weldedjoint is required to connect said bar sections. Consequently, fabrication procedure is greatly simplified and production costs are correspondingly lowered.

Generally speaking, the present method com prises bending a pair of bar elements upon themselves to provide each of the same with a pair of bar sections disposed in desired angular relationship to each other, then disposing the bent bar elements in corner-to-corner relationship with the four bar sections disposed in desired angular relationship to each other, and then welding the bar elements together at theircorners. In this way there obviously is accomplished: by means of only two bar elements and only a single welded joint all that has heretofore been accomplished by means of three bar elements and two welded joints. Moreover, the two-bar-element, singlewelded-joint structure has the advantage that it is stronger and sturdier than the three-bar-element, two-welded joint structure for reasons that are manifest.

If the bar stock is of a sectional shape including a web and one or more flanges extending from either or both sides of said web, the first step in accordance with the present method is to notch the flange, or flanges, of each of a pair of the stock bar elements at the point, or points, where said elements are to be bent to provide each of the same with its. respective bar sections. In Fig. 3 of the drawings this notching of the flanges II, II of one of the stock bar elements of T-shaped cross section is indicated at I2, I2. The notches, of \/,-shape, are alined with each other transversely of the bar element and, oi course, flare toward the outer edges of the flanges, beginning, preferably, "at points in alinement with the opposite faces of the web, respectively. By notching the bar elementthe same is, in effect, divided into a pair of bar sections, designated as S and S, respectively. Two bar elements are, of course, thus notched, the angularity of the flange ends formed by the notches depending, ofcourse, upon the angle to which the respective bar sections S, S, are to be bent relative to each other. i In this connection it is assumed in the present instance that the bar sections S, S are to be bent into right angular relationship. Accordingly, the notches I2, I! have ninety degree angles. That is to say, the flange'ends formed by said notches are disposed at angles of fortyfive degrees to the bar elements.

Following notching of the flanges II, II of a selected bar element the latter is bent in any suitable manner at said notches to bring their respective sections, S, S into desired angullar relationship to each other, in the present instance into right angular relationship. This has the effect of closing the notch a: at the inner sides of the bar elements and of opening the notch at the other side of the bar until the notch-formed endwalls of the flanges at the outer sides of the bar elements become alined with each other, as illustrated at y in Fig. 4 of the drawings. Whether the bar sections S, S are to be bent into right angular or other angular relationship, the notches l2, I! are formed so that upon bending of the bar sections to desired angular relationship, the notches at the inner sides of the bar elements are closed and-the notch-formed end walls of the flanges at the outer sides of the bar elements are brought into alinement with each other at right angles to a line bisectingthe angle formed by the sections S, S. v V

The next step of the present method resides in arranging the bent bar elements in corner-tocorner abutting relationship, in clamping or otherwise suitably holding them in this relationship,

.and in welding'them together at their corners,

asillustrated in Fig. 5 of the drawings. Either gas are, resistance, or projection welding may be employed, preferably the latter. In this case the step of bending the sections S, S into desired angular relationship to one another is followed by die-pressing or forming protuberances l3 at the outer corners of the web ill of one or both of the bar elements to be united to facilitate the .welding. The use of the protuberance or nib I3 greatly facilitates the formation of the weld in the respect that since it aids in quick melting of the metal at the nibs, the weld rapidly spreads outwardly along the surfaces 1!, and upon cooling and shrinking forms an'airtight Joint. In

any event, welding of-the bar elements prepared in the manner stated obviously results in a muntin bar structure comprising only two bar elements, each including two bar sections integral with and angularly related to each other, and in which the bar sections of the respective bar. elements are, in effect disposed in crossing relationship to each other. The structure thus is exceptionally strong and sturdy and its fabricationobviously may be effected with facility and, consequently, at low cost. l

The foregoing description has dealt with'the forming of only a single Jointbetween a pair of bar elements each including only two bar sections. In this connection it is apparent that any given bar element may be bent into any desired number of bar sections disposed in various different relationships to each other and that the joining together of such a bar element with another bar element embodying two or more bar sections having either the same relative disposition as the bar sections of the first bar element, or a different relative disposition, involves simply duplication of welded joints between the corners of the respective bar elements. For example, Fig. 7 of the drawingsillustrates that the successive bar sections S, S of a given bar element may have a stepped relationship to each other; Figure 8 of the drawings illustrates that successive bar sections 8,3 of a given bar element may be bent to provide the bar element with U-shaped formations, and Figure 9 illus-- trates a pair of stepped bar elements joined together in corner-to-corner relationship and'combined with a pair of corner bar elements of L- shape to provide a complete sash muntin structure which, when embodied in the sash, as shown, provides spaces to receive nine window panes. Obviously, the manner of bending the bar sections of the bar elements, and the manner of assembling or combining the different bar elements with each other, in any given muntin structure, may, within the purview of the invention, be varied within wide limits.

While any suitable apparatus may be employed for holding the different bar elements in correct relationship to each other during welding together of the same, and while any suitable apparatus may be employed for welding the elements together, one apparatus especially suited to simultaneously accomplish both of said purposes is illustrated in Figure 5 of the drawings. As shown, said apparatus comprises fixed clamp elements l4 and cooperating movable clamp elements l5 for gripping and holding a pair of bar elements in corner-to-corner relationship, and a pair of power operated electrodes Hi to urge the respective bar elements together at their corners and to maintain them urged together during the welding operation which, of course, is effected by including said electrodes in circuit with a proper source of electrical energy.

As to the fastening ofthe outer ends of the bar sections of any given muntin structure to the rails of a window sash or other frame element, that may be done by welding or in any other suitable manner with which thepresent invention is not concerned.

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be-understood that changes in the form, proportion and minor details of construction may be resorted to, without departf ing from the spirit of the invention and scope or the appended claims.

I claim:

1. The method of fabricating a muntin bar structure from bar elements each having a web and a lateral flange, which comprises forming in the flange of each bar element a V-shaped notch, bendingeach bar element upon itself at said notch to provide a pair of bar sections diverging relative to each other from the bend with their flanges disposed outwardly and the notch opened, arranging said bar elements in corner-to-corner relationship, and welding said elements together at their corners.

2. The method of fabricating a muntin bar structure from bar elements each having a web and a flange extending laterally from each side thereof, which comprises forming in each side portion of the flange of each bar element, at points alined transversely of the bar element, a V-shaped notch, bending each bar element upon itself at said notches to provide a pair of bar sections diverging relative to each other from the bend with the flange side portions thereof extending inwardly and outwardly, respectively, and to close the notch in the inner side portion of the flange and open the notch in the outerside portion of the flange, arranging the bar elements in corner-to-corner relationship, and welding said elements together attheircorners.

3. The method of fabricating a muntin bar structure which comprises bending each 01' a pair of bar elements upon itself to provide a pair of bar sections diverging relative to eachother from the bend, forming protuberances on the corner of at least one of said elements at the bend therein to facilitate resistance welding together of the elements at their corners, arrangingsaid elements in corner-to-corner relationship, and resistancewelding said elements together at their corners.

ELMON A. SCHOTTENBERG.

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